1/*
2 * Copyright 2002-2005, Instant802 Networks, Inc.
3 * Copyright 2005-2006, Devicescape Software, Inc.
4 * Copyright (c) 2006 Jiri Benc <jbenc@suse.cz>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11#include <linux/kernel.h>
12#include <linux/rtnetlink.h>
13#include <linux/module.h>
14#include <linux/slab.h>
15#include "rate.h"
16#include "ieee80211_i.h"
17#include "debugfs.h"
18
19struct rate_control_alg {
20	struct list_head list;
21	const struct rate_control_ops *ops;
22};
23
24static LIST_HEAD(rate_ctrl_algs);
25static DEFINE_MUTEX(rate_ctrl_mutex);
26
27static char *ieee80211_default_rc_algo = CONFIG_MAC80211_RC_DEFAULT;
28module_param(ieee80211_default_rc_algo, charp, 0644);
29MODULE_PARM_DESC(ieee80211_default_rc_algo,
30		 "Default rate control algorithm for mac80211 to use");
31
32void rate_control_rate_init(struct sta_info *sta)
33{
34	struct ieee80211_local *local = sta->sdata->local;
35	struct rate_control_ref *ref = sta->rate_ctrl;
36	struct ieee80211_sta *ista = &sta->sta;
37	void *priv_sta = sta->rate_ctrl_priv;
38	struct ieee80211_supported_band *sband;
39	struct ieee80211_chanctx_conf *chanctx_conf;
40
41	ieee80211_sta_set_rx_nss(sta);
42
43	if (!ref)
44		return;
45
46	rcu_read_lock();
47
48	chanctx_conf = rcu_dereference(sta->sdata->vif.chanctx_conf);
49	if (WARN_ON(!chanctx_conf)) {
50		rcu_read_unlock();
51		return;
52	}
53
54	sband = local->hw.wiphy->bands[chanctx_conf->def.chan->band];
55
56	spin_lock_bh(&sta->rate_ctrl_lock);
57	ref->ops->rate_init(ref->priv, sband, &chanctx_conf->def, ista,
58			    priv_sta);
59	spin_unlock_bh(&sta->rate_ctrl_lock);
60	rcu_read_unlock();
61	set_sta_flag(sta, WLAN_STA_RATE_CONTROL);
62}
63
64void rate_control_rate_update(struct ieee80211_local *local,
65				    struct ieee80211_supported_band *sband,
66				    struct sta_info *sta, u32 changed)
67{
68	struct rate_control_ref *ref = local->rate_ctrl;
69	struct ieee80211_sta *ista = &sta->sta;
70	void *priv_sta = sta->rate_ctrl_priv;
71	struct ieee80211_chanctx_conf *chanctx_conf;
72
73	if (ref && ref->ops->rate_update) {
74		rcu_read_lock();
75
76		chanctx_conf = rcu_dereference(sta->sdata->vif.chanctx_conf);
77		if (WARN_ON(!chanctx_conf)) {
78			rcu_read_unlock();
79			return;
80		}
81
82		spin_lock_bh(&sta->rate_ctrl_lock);
83		ref->ops->rate_update(ref->priv, sband, &chanctx_conf->def,
84				      ista, priv_sta, changed);
85		spin_unlock_bh(&sta->rate_ctrl_lock);
86		rcu_read_unlock();
87	}
88	drv_sta_rc_update(local, sta->sdata, &sta->sta, changed);
89}
90
91int ieee80211_rate_control_register(const struct rate_control_ops *ops)
92{
93	struct rate_control_alg *alg;
94
95	if (!ops->name)
96		return -EINVAL;
97
98	mutex_lock(&rate_ctrl_mutex);
99	list_for_each_entry(alg, &rate_ctrl_algs, list) {
100		if (!strcmp(alg->ops->name, ops->name)) {
101			/* don't register an algorithm twice */
102			WARN_ON(1);
103			mutex_unlock(&rate_ctrl_mutex);
104			return -EALREADY;
105		}
106	}
107
108	alg = kzalloc(sizeof(*alg), GFP_KERNEL);
109	if (alg == NULL) {
110		mutex_unlock(&rate_ctrl_mutex);
111		return -ENOMEM;
112	}
113	alg->ops = ops;
114
115	list_add_tail(&alg->list, &rate_ctrl_algs);
116	mutex_unlock(&rate_ctrl_mutex);
117
118	return 0;
119}
120EXPORT_SYMBOL(ieee80211_rate_control_register);
121
122void ieee80211_rate_control_unregister(const struct rate_control_ops *ops)
123{
124	struct rate_control_alg *alg;
125
126	mutex_lock(&rate_ctrl_mutex);
127	list_for_each_entry(alg, &rate_ctrl_algs, list) {
128		if (alg->ops == ops) {
129			list_del(&alg->list);
130			kfree(alg);
131			break;
132		}
133	}
134	mutex_unlock(&rate_ctrl_mutex);
135}
136EXPORT_SYMBOL(ieee80211_rate_control_unregister);
137
138static const struct rate_control_ops *
139ieee80211_try_rate_control_ops_get(const char *name)
140{
141	struct rate_control_alg *alg;
142	const struct rate_control_ops *ops = NULL;
143
144	if (!name)
145		return NULL;
146
147	mutex_lock(&rate_ctrl_mutex);
148	list_for_each_entry(alg, &rate_ctrl_algs, list) {
149		if (!strcmp(alg->ops->name, name)) {
150			ops = alg->ops;
151			break;
152		}
153	}
154	mutex_unlock(&rate_ctrl_mutex);
155	return ops;
156}
157
158/* Get the rate control algorithm. */
159static const struct rate_control_ops *
160ieee80211_rate_control_ops_get(const char *name)
161{
162	const struct rate_control_ops *ops;
163	const char *alg_name;
164
165	kernel_param_lock(THIS_MODULE);
166	if (!name)
167		alg_name = ieee80211_default_rc_algo;
168	else
169		alg_name = name;
170
171	ops = ieee80211_try_rate_control_ops_get(alg_name);
172	if (!ops && name)
173		/* try default if specific alg requested but not found */
174		ops = ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo);
175
176	/* try built-in one if specific alg requested but not found */
177	if (!ops && strlen(CONFIG_MAC80211_RC_DEFAULT))
178		ops = ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT);
179	kernel_param_unlock(THIS_MODULE);
180
181	return ops;
182}
183
184#ifdef CONFIG_MAC80211_DEBUGFS
185static ssize_t rcname_read(struct file *file, char __user *userbuf,
186			   size_t count, loff_t *ppos)
187{
188	struct rate_control_ref *ref = file->private_data;
189	int len = strlen(ref->ops->name);
190
191	return simple_read_from_buffer(userbuf, count, ppos,
192				       ref->ops->name, len);
193}
194
195static const struct file_operations rcname_ops = {
196	.read = rcname_read,
197	.open = simple_open,
198	.llseek = default_llseek,
199};
200#endif
201
202static struct rate_control_ref *rate_control_alloc(const char *name,
203					    struct ieee80211_local *local)
204{
205	struct dentry *debugfsdir = NULL;
206	struct rate_control_ref *ref;
207
208	ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL);
209	if (!ref)
210		return NULL;
211	ref->local = local;
212	ref->ops = ieee80211_rate_control_ops_get(name);
213	if (!ref->ops)
214		goto free;
215
216#ifdef CONFIG_MAC80211_DEBUGFS
217	debugfsdir = debugfs_create_dir("rc", local->hw.wiphy->debugfsdir);
218	local->debugfs.rcdir = debugfsdir;
219	debugfs_create_file("name", 0400, debugfsdir, ref, &rcname_ops);
220#endif
221
222	ref->priv = ref->ops->alloc(&local->hw, debugfsdir);
223	if (!ref->priv)
224		goto free;
225	return ref;
226
227free:
228	kfree(ref);
229	return NULL;
230}
231
232static void rate_control_free(struct rate_control_ref *ctrl_ref)
233{
234	ctrl_ref->ops->free(ctrl_ref->priv);
235
236#ifdef CONFIG_MAC80211_DEBUGFS
237	debugfs_remove_recursive(ctrl_ref->local->debugfs.rcdir);
238	ctrl_ref->local->debugfs.rcdir = NULL;
239#endif
240
241	kfree(ctrl_ref);
242}
243
244static bool rc_no_data_or_no_ack_use_min(struct ieee80211_tx_rate_control *txrc)
245{
246	struct sk_buff *skb = txrc->skb;
247	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
248	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
249	__le16 fc;
250
251	fc = hdr->frame_control;
252
253	return (info->flags & (IEEE80211_TX_CTL_NO_ACK |
254			       IEEE80211_TX_CTL_USE_MINRATE)) ||
255		!ieee80211_is_data(fc);
256}
257
258static void rc_send_low_basicrate(s8 *idx, u32 basic_rates,
259				  struct ieee80211_supported_band *sband)
260{
261	u8 i;
262
263	if (basic_rates == 0)
264		return; /* assume basic rates unknown and accept rate */
265	if (*idx < 0)
266		return;
267	if (basic_rates & (1 << *idx))
268		return; /* selected rate is a basic rate */
269
270	for (i = *idx + 1; i <= sband->n_bitrates; i++) {
271		if (basic_rates & (1 << i)) {
272			*idx = i;
273			return;
274		}
275	}
276
277	/* could not find a basic rate; use original selection */
278}
279
280static void __rate_control_send_low(struct ieee80211_hw *hw,
281				    struct ieee80211_supported_band *sband,
282				    struct ieee80211_sta *sta,
283				    struct ieee80211_tx_info *info,
284				    u32 rate_mask)
285{
286	int i;
287	u32 rate_flags =
288		ieee80211_chandef_rate_flags(&hw->conf.chandef);
289
290	if ((sband->band == IEEE80211_BAND_2GHZ) &&
291	    (info->flags & IEEE80211_TX_CTL_NO_CCK_RATE))
292		rate_flags |= IEEE80211_RATE_ERP_G;
293
294	info->control.rates[0].idx = 0;
295	for (i = 0; i < sband->n_bitrates; i++) {
296		if (!(rate_mask & BIT(i)))
297			continue;
298
299		if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
300			continue;
301
302		if (!rate_supported(sta, sband->band, i))
303			continue;
304
305		info->control.rates[0].idx = i;
306		break;
307	}
308	WARN_ONCE(i == sband->n_bitrates,
309		  "no supported rates (0x%x) in rate_mask 0x%x with flags 0x%x\n",
310		  sta ? sta->supp_rates[sband->band] : -1,
311		  rate_mask, rate_flags);
312
313	info->control.rates[0].count =
314		(info->flags & IEEE80211_TX_CTL_NO_ACK) ?
315		1 : hw->max_rate_tries;
316
317	info->control.skip_table = 1;
318}
319
320
321bool rate_control_send_low(struct ieee80211_sta *pubsta,
322			   void *priv_sta,
323			   struct ieee80211_tx_rate_control *txrc)
324{
325	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
326	struct ieee80211_supported_band *sband = txrc->sband;
327	struct sta_info *sta;
328	int mcast_rate;
329	bool use_basicrate = false;
330
331	if (!pubsta || !priv_sta || rc_no_data_or_no_ack_use_min(txrc)) {
332		__rate_control_send_low(txrc->hw, sband, pubsta, info,
333					txrc->rate_idx_mask);
334
335		if (!pubsta && txrc->bss) {
336			mcast_rate = txrc->bss_conf->mcast_rate[sband->band];
337			if (mcast_rate > 0) {
338				info->control.rates[0].idx = mcast_rate - 1;
339				return true;
340			}
341			use_basicrate = true;
342		} else if (pubsta) {
343			sta = container_of(pubsta, struct sta_info, sta);
344			if (ieee80211_vif_is_mesh(&sta->sdata->vif))
345				use_basicrate = true;
346		}
347
348		if (use_basicrate)
349			rc_send_low_basicrate(&info->control.rates[0].idx,
350					      txrc->bss_conf->basic_rates,
351					      sband);
352
353		return true;
354	}
355	return false;
356}
357EXPORT_SYMBOL(rate_control_send_low);
358
359static bool rate_idx_match_legacy_mask(s8 *rate_idx, int n_bitrates, u32 mask)
360{
361	int j;
362
363	/* See whether the selected rate or anything below it is allowed. */
364	for (j = *rate_idx; j >= 0; j--) {
365		if (mask & (1 << j)) {
366			/* Okay, found a suitable rate. Use it. */
367			*rate_idx = j;
368			return true;
369		}
370	}
371
372	/* Try to find a higher rate that would be allowed */
373	for (j = *rate_idx + 1; j < n_bitrates; j++) {
374		if (mask & (1 << j)) {
375			/* Okay, found a suitable rate. Use it. */
376			*rate_idx = j;
377			return true;
378		}
379	}
380	return false;
381}
382
383static bool rate_idx_match_mcs_mask(s8 *rate_idx, u8 *mcs_mask)
384{
385	int i, j;
386	int ridx, rbit;
387
388	ridx = *rate_idx / 8;
389	rbit = *rate_idx % 8;
390
391	/* sanity check */
392	if (ridx < 0 || ridx >= IEEE80211_HT_MCS_MASK_LEN)
393		return false;
394
395	/* See whether the selected rate or anything below it is allowed. */
396	for (i = ridx; i >= 0; i--) {
397		for (j = rbit; j >= 0; j--)
398			if (mcs_mask[i] & BIT(j)) {
399				*rate_idx = i * 8 + j;
400				return true;
401			}
402		rbit = 7;
403	}
404
405	/* Try to find a higher rate that would be allowed */
406	ridx = (*rate_idx + 1) / 8;
407	rbit = (*rate_idx + 1) % 8;
408
409	for (i = ridx; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
410		for (j = rbit; j < 8; j++)
411			if (mcs_mask[i] & BIT(j)) {
412				*rate_idx = i * 8 + j;
413				return true;
414			}
415		rbit = 0;
416	}
417	return false;
418}
419
420static bool rate_idx_match_vht_mcs_mask(s8 *rate_idx, u16 *vht_mask)
421{
422	int i, j;
423	int ridx, rbit;
424
425	ridx = *rate_idx >> 4;
426	rbit = *rate_idx & 0xf;
427
428	if (ridx < 0 || ridx >= NL80211_VHT_NSS_MAX)
429		return false;
430
431	/* See whether the selected rate or anything below it is allowed. */
432	for (i = ridx; i >= 0; i--) {
433		for (j = rbit; j >= 0; j--) {
434			if (vht_mask[i] & BIT(j)) {
435				*rate_idx = (i << 4) | j;
436				return true;
437			}
438		}
439		rbit = 15;
440	}
441
442	/* Try to find a higher rate that would be allowed */
443	ridx = (*rate_idx + 1) >> 4;
444	rbit = (*rate_idx + 1) & 0xf;
445
446	for (i = ridx; i < NL80211_VHT_NSS_MAX; i++) {
447		for (j = rbit; j < 16; j++) {
448			if (vht_mask[i] & BIT(j)) {
449				*rate_idx = (i << 4) | j;
450				return true;
451			}
452		}
453		rbit = 0;
454	}
455	return false;
456}
457
458static void rate_idx_match_mask(s8 *rate_idx, u16 *rate_flags,
459				struct ieee80211_supported_band *sband,
460				enum nl80211_chan_width chan_width,
461				u32 mask,
462				u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN],
463				u16 vht_mask[NL80211_VHT_NSS_MAX])
464{
465	if (*rate_flags & IEEE80211_TX_RC_VHT_MCS) {
466		/* handle VHT rates */
467		if (rate_idx_match_vht_mcs_mask(rate_idx, vht_mask))
468			return;
469
470		*rate_idx = 0;
471		/* keep protection flags */
472		*rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
473				IEEE80211_TX_RC_USE_CTS_PROTECT |
474				IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
475
476		*rate_flags |= IEEE80211_TX_RC_MCS;
477		if (chan_width == NL80211_CHAN_WIDTH_40)
478			*rate_flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
479
480		if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
481			return;
482
483		/* also try the legacy rates. */
484		*rate_flags &= ~(IEEE80211_TX_RC_MCS |
485				 IEEE80211_TX_RC_40_MHZ_WIDTH);
486		if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
487					       mask))
488			return;
489	} else if (*rate_flags & IEEE80211_TX_RC_MCS) {
490		/* handle HT rates */
491		if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
492			return;
493
494		/* also try the legacy rates. */
495		*rate_idx = 0;
496		/* keep protection flags */
497		*rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
498				IEEE80211_TX_RC_USE_CTS_PROTECT |
499				IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
500		if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
501					       mask))
502			return;
503	} else {
504		/* handle legacy rates */
505		if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
506					       mask))
507			return;
508
509		/* if HT BSS, and we handle a data frame, also try HT rates */
510		switch (chan_width) {
511		case NL80211_CHAN_WIDTH_20_NOHT:
512		case NL80211_CHAN_WIDTH_5:
513		case NL80211_CHAN_WIDTH_10:
514			return;
515		default:
516			break;
517		}
518
519		*rate_idx = 0;
520		/* keep protection flags */
521		*rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
522				IEEE80211_TX_RC_USE_CTS_PROTECT |
523				IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
524
525		*rate_flags |= IEEE80211_TX_RC_MCS;
526
527		if (chan_width == NL80211_CHAN_WIDTH_40)
528			*rate_flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
529
530		if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
531			return;
532	}
533
534	/*
535	 * Uh.. No suitable rate exists. This should not really happen with
536	 * sane TX rate mask configurations. However, should someone manage to
537	 * configure supported rates and TX rate mask in incompatible way,
538	 * allow the frame to be transmitted with whatever the rate control
539	 * selected.
540	 */
541}
542
543static void rate_fixup_ratelist(struct ieee80211_vif *vif,
544				struct ieee80211_supported_band *sband,
545				struct ieee80211_tx_info *info,
546				struct ieee80211_tx_rate *rates,
547				int max_rates)
548{
549	struct ieee80211_rate *rate;
550	bool inval = false;
551	int i;
552
553	/*
554	 * Set up the RTS/CTS rate as the fastest basic rate
555	 * that is not faster than the data rate unless there
556	 * is no basic rate slower than the data rate, in which
557	 * case we pick the slowest basic rate
558	 *
559	 * XXX: Should this check all retry rates?
560	 */
561	if (!(rates[0].flags &
562	      (IEEE80211_TX_RC_MCS | IEEE80211_TX_RC_VHT_MCS))) {
563		u32 basic_rates = vif->bss_conf.basic_rates;
564		s8 baserate = basic_rates ? ffs(basic_rates) - 1 : 0;
565
566		rate = &sband->bitrates[rates[0].idx];
567
568		for (i = 0; i < sband->n_bitrates; i++) {
569			/* must be a basic rate */
570			if (!(basic_rates & BIT(i)))
571				continue;
572			/* must not be faster than the data rate */
573			if (sband->bitrates[i].bitrate > rate->bitrate)
574				continue;
575			/* maximum */
576			if (sband->bitrates[baserate].bitrate <
577			     sband->bitrates[i].bitrate)
578				baserate = i;
579		}
580
581		info->control.rts_cts_rate_idx = baserate;
582	}
583
584	for (i = 0; i < max_rates; i++) {
585		/*
586		 * make sure there's no valid rate following
587		 * an invalid one, just in case drivers don't
588		 * take the API seriously to stop at -1.
589		 */
590		if (inval) {
591			rates[i].idx = -1;
592			continue;
593		}
594		if (rates[i].idx < 0) {
595			inval = true;
596			continue;
597		}
598
599		/*
600		 * For now assume MCS is already set up correctly, this
601		 * needs to be fixed.
602		 */
603		if (rates[i].flags & IEEE80211_TX_RC_MCS) {
604			WARN_ON(rates[i].idx > 76);
605
606			if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) &&
607			    info->control.use_cts_prot)
608				rates[i].flags |=
609					IEEE80211_TX_RC_USE_CTS_PROTECT;
610			continue;
611		}
612
613		if (rates[i].flags & IEEE80211_TX_RC_VHT_MCS) {
614			WARN_ON(ieee80211_rate_get_vht_mcs(&rates[i]) > 9);
615			continue;
616		}
617
618		/* set up RTS protection if desired */
619		if (info->control.use_rts) {
620			rates[i].flags |= IEEE80211_TX_RC_USE_RTS_CTS;
621			info->control.use_cts_prot = false;
622		}
623
624		/* RC is busted */
625		if (WARN_ON_ONCE(rates[i].idx >= sband->n_bitrates)) {
626			rates[i].idx = -1;
627			continue;
628		}
629
630		rate = &sband->bitrates[rates[i].idx];
631
632		/* set up short preamble */
633		if (info->control.short_preamble &&
634		    rate->flags & IEEE80211_RATE_SHORT_PREAMBLE)
635			rates[i].flags |= IEEE80211_TX_RC_USE_SHORT_PREAMBLE;
636
637		/* set up G protection */
638		if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) &&
639		    info->control.use_cts_prot &&
640		    rate->flags & IEEE80211_RATE_ERP_G)
641			rates[i].flags |= IEEE80211_TX_RC_USE_CTS_PROTECT;
642	}
643}
644
645
646static void rate_control_fill_sta_table(struct ieee80211_sta *sta,
647					struct ieee80211_tx_info *info,
648					struct ieee80211_tx_rate *rates,
649					int max_rates)
650{
651	struct ieee80211_sta_rates *ratetbl = NULL;
652	int i;
653
654	if (sta && !info->control.skip_table)
655		ratetbl = rcu_dereference(sta->rates);
656
657	/* Fill remaining rate slots with data from the sta rate table. */
658	max_rates = min_t(int, max_rates, IEEE80211_TX_RATE_TABLE_SIZE);
659	for (i = 0; i < max_rates; i++) {
660		if (i < ARRAY_SIZE(info->control.rates) &&
661		    info->control.rates[i].idx >= 0 &&
662		    info->control.rates[i].count) {
663			if (rates != info->control.rates)
664				rates[i] = info->control.rates[i];
665		} else if (ratetbl) {
666			rates[i].idx = ratetbl->rate[i].idx;
667			rates[i].flags = ratetbl->rate[i].flags;
668			if (info->control.use_rts)
669				rates[i].count = ratetbl->rate[i].count_rts;
670			else if (info->control.use_cts_prot)
671				rates[i].count = ratetbl->rate[i].count_cts;
672			else
673				rates[i].count = ratetbl->rate[i].count;
674		} else {
675			rates[i].idx = -1;
676			rates[i].count = 0;
677		}
678
679		if (rates[i].idx < 0 || !rates[i].count)
680			break;
681	}
682}
683
684static bool rate_control_cap_mask(struct ieee80211_sub_if_data *sdata,
685				  struct ieee80211_supported_band *sband,
686				  struct ieee80211_sta *sta, u32 *mask,
687				  u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN],
688				  u16 vht_mask[NL80211_VHT_NSS_MAX])
689{
690	u32 i, flags;
691
692	*mask = sdata->rc_rateidx_mask[sband->band];
693	flags = ieee80211_chandef_rate_flags(&sdata->vif.bss_conf.chandef);
694	for (i = 0; i < sband->n_bitrates; i++) {
695		if ((flags & sband->bitrates[i].flags) != flags)
696			*mask &= ~BIT(i);
697	}
698
699	if (*mask == (1 << sband->n_bitrates) - 1 &&
700	    !sdata->rc_has_mcs_mask[sband->band] &&
701	    !sdata->rc_has_vht_mcs_mask[sband->band])
702		return false;
703
704	if (sdata->rc_has_mcs_mask[sband->band])
705		memcpy(mcs_mask, sdata->rc_rateidx_mcs_mask[sband->band],
706		       IEEE80211_HT_MCS_MASK_LEN);
707	else
708		memset(mcs_mask, 0xff, IEEE80211_HT_MCS_MASK_LEN);
709
710	if (sdata->rc_has_vht_mcs_mask[sband->band])
711		memcpy(vht_mask, sdata->rc_rateidx_vht_mcs_mask[sband->band],
712		       sizeof(u16) * NL80211_VHT_NSS_MAX);
713	else
714		memset(vht_mask, 0xff, sizeof(u16) * NL80211_VHT_NSS_MAX);
715
716	if (sta) {
717		__le16 sta_vht_cap;
718		u16 sta_vht_mask[NL80211_VHT_NSS_MAX];
719
720		/* Filter out rates that the STA does not support */
721		*mask &= sta->supp_rates[sband->band];
722		for (i = 0; i < IEEE80211_HT_MCS_MASK_LEN; i++)
723			mcs_mask[i] &= sta->ht_cap.mcs.rx_mask[i];
724
725		sta_vht_cap = sta->vht_cap.vht_mcs.rx_mcs_map;
726		ieee80211_get_vht_mask_from_cap(sta_vht_cap, sta_vht_mask);
727		for (i = 0; i < NL80211_VHT_NSS_MAX; i++)
728			vht_mask[i] &= sta_vht_mask[i];
729	}
730
731	return true;
732}
733
734static void
735rate_control_apply_mask_ratetbl(struct sta_info *sta,
736				struct ieee80211_supported_band *sband,
737				struct ieee80211_sta_rates *rates)
738{
739	int i;
740	u32 mask;
741	u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
742	u16 vht_mask[NL80211_VHT_NSS_MAX];
743	enum nl80211_chan_width chan_width;
744
745	if (!rate_control_cap_mask(sta->sdata, sband, &sta->sta, &mask,
746				   mcs_mask, vht_mask))
747		return;
748
749	chan_width = sta->sdata->vif.bss_conf.chandef.width;
750	for (i = 0; i < IEEE80211_TX_RATE_TABLE_SIZE; i++) {
751		if (rates->rate[i].idx < 0)
752			break;
753
754		rate_idx_match_mask(&rates->rate[i].idx, &rates->rate[i].flags,
755				    sband, chan_width, mask, mcs_mask,
756				    vht_mask);
757	}
758}
759
760static void rate_control_apply_mask(struct ieee80211_sub_if_data *sdata,
761				    struct ieee80211_sta *sta,
762				    struct ieee80211_supported_band *sband,
763				    struct ieee80211_tx_rate *rates,
764				    int max_rates)
765{
766	enum nl80211_chan_width chan_width;
767	u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
768	u32 mask;
769	u16 rate_flags, vht_mask[NL80211_VHT_NSS_MAX];
770	int i;
771
772	/*
773	 * Try to enforce the rateidx mask the user wanted. skip this if the
774	 * default mask (allow all rates) is used to save some processing for
775	 * the common case.
776	 */
777	if (!rate_control_cap_mask(sdata, sband, sta, &mask, mcs_mask,
778				   vht_mask))
779		return;
780
781	/*
782	 * Make sure the rate index selected for each TX rate is
783	 * included in the configured mask and change the rate indexes
784	 * if needed.
785	 */
786	chan_width = sdata->vif.bss_conf.chandef.width;
787	for (i = 0; i < max_rates; i++) {
788		/* Skip invalid rates */
789		if (rates[i].idx < 0)
790			break;
791
792		rate_flags = rates[i].flags;
793		rate_idx_match_mask(&rates[i].idx, &rate_flags, sband,
794				    chan_width, mask, mcs_mask, vht_mask);
795		rates[i].flags = rate_flags;
796	}
797}
798
799void ieee80211_get_tx_rates(struct ieee80211_vif *vif,
800			    struct ieee80211_sta *sta,
801			    struct sk_buff *skb,
802			    struct ieee80211_tx_rate *dest,
803			    int max_rates)
804{
805	struct ieee80211_sub_if_data *sdata;
806	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
807	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
808	struct ieee80211_supported_band *sband;
809
810	rate_control_fill_sta_table(sta, info, dest, max_rates);
811
812	if (!vif)
813		return;
814
815	sdata = vif_to_sdata(vif);
816	sband = sdata->local->hw.wiphy->bands[info->band];
817
818	if (ieee80211_is_data(hdr->frame_control))
819		rate_control_apply_mask(sdata, sta, sband, dest, max_rates);
820
821	if (dest[0].idx < 0)
822		__rate_control_send_low(&sdata->local->hw, sband, sta, info,
823					sdata->rc_rateidx_mask[info->band]);
824
825	if (sta)
826		rate_fixup_ratelist(vif, sband, info, dest, max_rates);
827}
828EXPORT_SYMBOL(ieee80211_get_tx_rates);
829
830void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
831			   struct sta_info *sta,
832			   struct ieee80211_tx_rate_control *txrc)
833{
834	struct rate_control_ref *ref = sdata->local->rate_ctrl;
835	void *priv_sta = NULL;
836	struct ieee80211_sta *ista = NULL;
837	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
838	int i;
839
840	if (sta && test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) {
841		ista = &sta->sta;
842		priv_sta = sta->rate_ctrl_priv;
843	}
844
845	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
846		info->control.rates[i].idx = -1;
847		info->control.rates[i].flags = 0;
848		info->control.rates[i].count = 0;
849	}
850
851	if (ieee80211_hw_check(&sdata->local->hw, HAS_RATE_CONTROL))
852		return;
853
854	if (ista) {
855		spin_lock_bh(&sta->rate_ctrl_lock);
856		ref->ops->get_rate(ref->priv, ista, priv_sta, txrc);
857		spin_unlock_bh(&sta->rate_ctrl_lock);
858	} else {
859		ref->ops->get_rate(ref->priv, NULL, NULL, txrc);
860	}
861
862	if (ieee80211_hw_check(&sdata->local->hw, SUPPORTS_RC_TABLE))
863		return;
864
865	ieee80211_get_tx_rates(&sdata->vif, ista, txrc->skb,
866			       info->control.rates,
867			       ARRAY_SIZE(info->control.rates));
868}
869
870int rate_control_set_rates(struct ieee80211_hw *hw,
871			   struct ieee80211_sta *pubsta,
872			   struct ieee80211_sta_rates *rates)
873{
874	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
875	struct ieee80211_sta_rates *old;
876	struct ieee80211_supported_band *sband;
877
878	sband = hw->wiphy->bands[ieee80211_get_sdata_band(sta->sdata)];
879	rate_control_apply_mask_ratetbl(sta, sband, rates);
880	/*
881	 * mac80211 guarantees that this function will not be called
882	 * concurrently, so the following RCU access is safe, even without
883	 * extra locking. This can not be checked easily, so we just set
884	 * the condition to true.
885	 */
886	old = rcu_dereference_protected(pubsta->rates, true);
887	rcu_assign_pointer(pubsta->rates, rates);
888	if (old)
889		kfree_rcu(old, rcu_head);
890
891	drv_sta_rate_tbl_update(hw_to_local(hw), sta->sdata, pubsta);
892
893	return 0;
894}
895EXPORT_SYMBOL(rate_control_set_rates);
896
897int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
898				 const char *name)
899{
900	struct rate_control_ref *ref;
901
902	ASSERT_RTNL();
903
904	if (local->open_count)
905		return -EBUSY;
906
907	if (ieee80211_hw_check(&local->hw, HAS_RATE_CONTROL)) {
908		if (WARN_ON(!local->ops->set_rts_threshold))
909			return -EINVAL;
910		return 0;
911	}
912
913	ref = rate_control_alloc(name, local);
914	if (!ref) {
915		wiphy_warn(local->hw.wiphy,
916			   "Failed to select rate control algorithm\n");
917		return -ENOENT;
918	}
919
920	WARN_ON(local->rate_ctrl);
921	local->rate_ctrl = ref;
922
923	wiphy_debug(local->hw.wiphy, "Selected rate control algorithm '%s'\n",
924		    ref->ops->name);
925
926	return 0;
927}
928
929void rate_control_deinitialize(struct ieee80211_local *local)
930{
931	struct rate_control_ref *ref;
932
933	ref = local->rate_ctrl;
934
935	if (!ref)
936		return;
937
938	local->rate_ctrl = NULL;
939	rate_control_free(ref);
940}
941
942